Mu-halophenoxy silane

ABSTRACT

NEW COMPOUNDS OF THE CLASS REPRESENTATIVE OF WHICH ARE M-HALOPHENOXY ALKYL SILANES AND M-HALOPHENOXY SILANES WHICH ARE USEFUL AS FUNCTIONAL FLUIDS, MORE PARTICULARLY FOR USE AS HYDRAULIC FLUIDS.

United States Patent 3,576,833 m-HALOPHENOXY SILANE William C. Hammann, Creve Coeur, and Charles F.

Hobbs, Des Peres, Mo., assignors to Monsanto Company, St. Louis, M0. N Drawing. Filed May 22, 1968, Ser. No. 731,321 Int. Cl. C07f 7/06, 7/18 U.S. Cl. 260-448.8 1 Claim ABSTRACT OF THE DISCLOSURE New compounds of the class representative of which are m-halophenoxy alkyl silanes and m-halophenoxy silanes which are useful as functional fluids, more particularly for use as hydraulic fluids.

This invention relates to certain new m-halophenoxy alkyl silanes, m-halophenoxy silanes and the use of said compounds as functional fluids.

Many different types of materials are utilized as functional fluids and functional fluids are used in many different types of applications. Such fluids have been used as electronic coolants, diffusion pump fluids, synthetic lubricants, damping fluids, bases for greases, force transmission fluids (hydraulic fluids), heat transfer fluids, die casting release agents in metal extrusion processes and as filter mediums for air conditioning systems. Because of the wide variety of applications and the varied conditions under which functional fluids are utilized, the properties desired in a good functional fluid necessarily vary with the particular application in which it is to be utilized with each individual application requiring a functional fluid having a specific class of properties.

Of the foregoing the use of functional fluids as hydraulic fluids, particularly aircraft hydraulic fluids, has posed what is probably a most difficult area of application. Thus, the hydraulic power systems of aircraft for operating various mechanisms of an airplane impose certain functional and use requirements on the hydraulic fluid used. Thus, such a fluid should be as highly non-flammable as possible and must be sufficiently non-flammable to satisfy aircraft requirements for fire resistance. The viscosity characteristics of the fluid must be such that it may be used over a wide temperature range; that is, adequately high viscosity at high temperature, low viscosity at low temperature and a low rate of change of viscosity with temperature. Such temperature range is generally from about 40 F. to about 350 F. Its volatility should be low at elevated temperatures of use and the volatility should be balanced; that is, selective evaporation or volatilization of any important component should not take place at the high temperatures of use. It should possess sufficient lubricity and mechanical stability to enable it to be used in the self-lubricated pumps, valves, etc. employed in the hydraulic systems of aircraft which are exceedingly severe on the fluid used. It should possess thermal and chemical stability in order to resist decomposition. It should also not deteriorate the gaskets or packings of the hydraulic system or adversely affect the materials of which the system is constructed.

It has now been found that a functional fluid which has excellent physical properties, and which is particularly suitable for use as an aircraft fire resistant hydraulic fluid is obtained through the use of a compound or mixtures of compounds represented by the formula wherein each R is alkyl having from 1 to 4 carbon atoms,

each X is selected from the group consisting of bromo and chloro and n is a whole number having a value of 2 to 4.

The compounds of this invention can be prepared by reacting a tetrahalo silane, a terhalo alkyl silane or a dihalo dialkyl silane with a m-halophenol. A solvent can be utilized in preparing the compounds of this invention such as pyridine, triethylamine and dimethyl aniline. In general, the compounds are prepared in the absence of solvent at a temperature of from about 50 to about 275 C. for a period of from about 1 to about 36 hours. The mole ratios that are used of necessity vary according to the specific m-halophenoxy silane to be produced. In gen eral, however, the ratio of from about 3.0 to 3.3 moles of m-halophenol to 1 mole of trihalo alkyl silane is utilized to prepare the tris(m-halophenoxy) alkyl silanes, whereas to prepare the bis(m-halophenoxy) dialkyl silanes a mole ratio of about 2.0 to ratios of 2.2 m-halophenol to 1 mole of dihalo dialkyl silane is utilized. The preparation of tetra-m-halophenoxy silanes in general require a mole ratio of m-halophenol to tetrahalo silane of about 4 to l. The by-product HCl which can be formed in preparing the compounds of this invention can be removed by applying a slight vacuum to the reaction system or by purging the system with an inert gas such as nitrogen or allowing the HCl to evolve during the course of the reaction. A compound prepared utilizing the process as set forth above can be distilled under reduced pressure. In addition to preparing a specific compound of this invention, mixtures of compounds of this invention can be prepared by utilizing, for example, two different halo silanes or halo alkyl silanes, two diflerent m-halophenols or a combination thereof. In addition, the mixtures of individual compounds can be separated by fractional distillation to prepare the pure individual compounds which would have, for example, two different halogens attached to the phenyl ring. In addition, this invention contemplates that mixtures of individual compounds of this invention can be prepared by mixing individual compounds to prepare a functional fluid composition. It is contemplated within the scope of this invention that mixtures of compounds of this invention are particularly adaptable for use as functional fluids.

Typical examples of alkyl are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

Typical examples of the compounds of this invention are his (m-bromophenoxy) dimethyl silane, bis(m-brornophenoxy) diethyl silane,

bis m-bromophenoxy dipropyl silane,

bis (m-bromophenoxy) diisopropyl silane,

bis (m-bromophenoxy) dibutyl silane,

bis (m-bromophenoxy diisobutyl silane,

bis m-bromophenoxy di-tert-butyl silane, bis(m-chlorophenoxy)dimethyl silane,

bis (m-chlorophenoxy) diethyl silane,

bis m-chlorophenoxy) dipropyl silane, bis(m-chlorophenoxy) diisopropyl silane,

bis (m-chlorophenoxy dibutyl silane,

bis (m-chlorophenoxy) diisobutyl silane,

bis m-chlorophenoxy) di-tert-butyl silane, (m-bromophenoxy) (m-chlorophenoxy)dimethyl silane, (m-bromophenoxy) (m-chlorophenoxy) diethyl silane, (m-bromophenoxy) (m-chlorophenoxy) dipropyl silane, (m-bromophenoxy) (m-chlorophenoxy) diisopropyl silane, (m-bromophenoxy) (m-chlorophenoxy) dibutyl silane, bis(m-brotnophenoxy) methyl ethyl silane, bis(m-bromophenoxy) methyl butyl silane, bis(m-bromophenoxy) ethyl propyl silane, bis(m-bromophenoxy) propyl butyl silane, bis(m-bromophenoxy) isopropyl butyl silane,

bis(m-bromophenoxy) isopropyl isobutyl silane, bis (m-chlorophenoxy) methyl ethyl silane, bis(m-chlorophenoxy) methyl propyl silane, bis(m-chlorophenoxy) methyl butyl silane, bis(m-chlorophenoxy) methyl isobutyl silane, bis(m-chlorophenoxy) ethyl propyl silane, bis(m-chlorophenoxy) ethyl isopropyl silane, bis(m-chlorophenoxy) ethyl butyl silane, bis(m-chlorophenoxy) propyl butyl silane, (m-bromophenoxy) (m-chlorophenoxy) methyl ethyl silane (m-bromophenoxy) (m-chlorophenoxy) methyl propyl silane, (m-bromophenoxy) (m-chlorophenoxy) methyl butyl silane, (m-bromophenoxy) (m-chlorophenoxy) ethyl butyl silane, (m-bromophenoxy) (m-chlorophenoxy) propyl butyl silane, tris(m-bromophenoxy) methyl silane, tris(n1bromophenoxy) ethyl silane, tris(m-brornophenoxy) propyl silane, tris(m-bromophenoxy) butyl silane, tris(m-bromophenoxy) trisisobutyl silane, tris(m-bromophenoxy)-tert-butyl silane, tris(m-chlorophenoxy) methyl silane, tris (m-chlorophenoxy) ethyl silane, tris (m-chlorophenoxy) propyl silane, tris(m-chlorophenoxy) butyl silane, bis(m-bromophenoxy) (m-chlorophenoxy) methyl silane, bis (m-bromophenoxy) (m-chlorophenoxy) ethyl silane, bis(m-bromophenoxy) (rn-chlorophenoxy) propyl silane, bis(m-bromophenoxy) (m-chlorophenoxy)isobutyl silane, (rn-bromophenoxy)-bis(m-chlorophenoxy) methyl silane, (m-bromophenoxy)-bis (m-chlorophenoxy) ethyl silane, (m-bromophenoxy)-bis(m-chlorophenoxy) propyl silane, (m-bromophenoxy)-bis(m-chlorophenoxy) butyl silane, bis(m-bromophenoxy) -bis (m-chlorophenoxy) silane, tris (m-bromophenoxy) (m-chlorophenoxy) silane, tris (m-chlorophenoxy) (m-bromophenoxy) tetra(m-bromophenoxy) silane and tetra(m-chlorophenoxy silane.

The preparation or" the compounds of this invention are illustrated by the following non-limiting examples.

EXAMPLE 1 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 138.4 grams (0.8 mole) of m-bromophenol and 46 ml. (49.0 grams, 0.38 mole) of dimethyl dichloro silane. The mixture is heated to 80-90 C. for a period of about 12 hours during which time hydrogen chloride gas is evolved. The product is distilled and 118.0 grams of material boiling at 123-135 C. at 0.10 mm. is obtained. Upon redistillation at 0.08-0.07 mm. bis (m-bromophenoxy) dimethyl silane is obtained having a refractive index n of 1.5719, a percent carbon of 42.01, a percent hydrogen of 3.70, a percent bromine of 39.89 and a percent silicon of 7.06. An infrared spectrum of his (m-bromophenoxy) dimethyl silane shows absorption bands characteristic of CH aromatic, CH aliphatic and SiCH OSiO and meta substitution.

EXAMPLE 2 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.90 mole of m-bromophenol and 0.4 mole of diethyl dichloro silane. The mixture is heated to 105 C. for a period of about 16 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.05-0.l mm. bis(m-bromophenoxy) diethyl silane is obtained.

EXAMPLE 3 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.86 mole of m-bromophenol and 0.38 mole of diisopropyl dichloro silane. The mixture is heated to 87 C. for a period of about 12 hours and at 140 C. for an additional 8 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.070.1 mm. bis(m-bromophenoxy) diisopropyl silane is obtained.

EXAMPLE 4 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.86 mole of m-bromophenol and 0.38 mole of dibutyl dichloro silane. The mixture is heated to 112 C. for a period of about 17 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.05-0.09 mm. bis(m-bromophenoxy) dibutyl silane is obtained.

EXAMPLE 5 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 1.10 moles of m-chlorophenol and 0.50 mole of dimethyl dichloro silane. The mixture is heated to -90 C. for a period of about 10 hours and at 130 C. for an additional 12 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.08- 0.13 mm. bis(m-chlorophenoxy) dimethyl silane' is obtained.

EXAMPLE 7 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.60 mole of m-chlorophenol, 0.60 mole of m-bromophenol and 0.53 mole of dipropyl dichloro silane. The mixture is heated to C. for a period of about 10 hours and at 134 C. for an additional 8 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.04-0.08 mm. (m-bromophenoxy) (m-chlorophenoxy) dipropyl silane is obtained.

EXAMPLE 9 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.80 mole of m-bromophenol, 0.40 mole of m-chlorophenol and 0.40 mole of methyl trichlorosilane. The mixture is heated to C. for a period of about 24 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at -0.05-0.1 mm. bis(m-bromophenoxy) (m-chlorophenoxy) methyl silane is obtained.

EXAMPLE 10 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.80 mole of m-bromophenol, 0.40 mole of m-chlorophenol and 0.39 mole of propyl trichlorosilane. The mixture is heated to 114 C. for a period of about 10 hours and at C. for an additional 8 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.03-0.08 mm. bis(rn-bromophenoxy) (mchlorophenoxy) propyl silane is obtained.

EXAMPLE 11 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.4 mole of m-bromophenol, 0.80 mole of m-chlorophenol and 0.38 mole of methyl trichlorosilane. The mixture is heated to 80-90 C. for a period of about 16 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.03-0.1 mm. bis(m-chlorophenoxy) (m-bromophenoxy) methyl silane is obtained.

EXAMPLE 12 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.87 mole of m-chlorophenol and 0.21 mole of tetrachloro silane. The mixture is heated to 108 C. for a period of about 16 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.03-0.09 mm. tetra(m-chlorophenoxy) silane is obtained.

EXAMPLE 13 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.88 mole of m-bromophenol and 0.21 mole of tetrachloro silane. The mixture is heated to 80-90 C. for a period of about 12 hours and at 125 C. for an additional 10 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.03-0.08 mm. tetra(mbromophenoxy) silane is obtained.

EXAMPLE 14 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.42 mole of m-bromophenol, 0.42 mole of m-chlorophenol and 0.205 mole of tetrachloro silane. The mixture is heated to 85 C. for a period of about 10 hours and at 132 C. for an additional 11 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.030.08 mm. bis(m-bromophenoxy)-bis (m-chlorophenoxy) silane is obtained.

EXAMPLE 15 To a suitable reaction flask equipped with condenser, stirrer and outlet tube is charged 0.92 mole of m-bromophenol and 0.3 mole of methyl trihalo silane. The mixture is heated to 80-90 C. for a period of about 12 hours during which time hydrogen chloride gas is evolved. The reaction product is distilled and upon redistillation at 0.05- 0.1 mm. tris (m-bromophenoxy) methyl silane is obtained.

The compounds of this invention exhibit fire resistant properties and have excellent low temperature viscosity as compared to the corresponding para derivative. More particularly, the compound bis(m-bromophenoxy) dimethyl silane had a viscosity at 30 F. of 8,709 centistokes (kinematic viscosity), Whereas the corresponding para derivative had a viscosity in centistokes at 30 F. of 39,921. This unexpected reduction in low temperature viscosity of the compounds of this invention is of considerable importance in hydraulic systems which are subject to environmental temperatures existing below F. Thus, for example, in aircraft hydraulic systems, temperatures can be reached which can vary from, for example, F. to 50 F. At these temperatures a low viscosity fluid offers a tremendous advantage in start-up capability of the hydraulic system.

As a result of the excellent properties of the compounds and mixtures of compounds of this invention, improved hydraulic pressure devices can be prepared in accordance with this invention which comprise in combination a fluid chamber and an actuating fluid composition in said chamber, said fluid comprising a major amount of one or more of the compounds of this invention. In general one or more compounds of this invention comprise about a major amount by weight of the total fluid composition, more preferably comprising about 65% by weight, and still more preferably at least about 85% by weight. Thus, this invention relates to a method of operating a hydraulic pressure device wherein a displaceable force is trans mitted to a displaceable member by means of a hydraulic fluid wherein the improvement comprises employing as said fluid one or more compounds of this invention in a major amount, the remainder of said functional fluid being made up of additional functional fluid base stocks which are blended with one or more compounds of this invention. In addition, one or more compounds of this invention can be utilized as the sole fluid optionally containing additives. Thus, the compounds of this invention can be blended with other fluid base stocks for use in hydraulic systems. In such a system, the parts which are so lubricated include the frictional surfaces of the source of power, namely the pump, valves, operating pistons and cylinder, fluid motors, and in some cases, for machine tools, the ways, tables and slides. The hydraulic system may be of either the constant-volume or the variable volume type of system.

The pumps may be of various types, including centrifugal pumps, jet pumps, turbine vane, liquid piston gas compressors, piston-type pump, more particularly the variable-stroke piston pump, the variable-discharge or variable displacement piston pump, radial-piston pump, axial-piston pump, in which a pivoted cylinder block is adjusted at various angles with the piston assembly, for example, the Vickers Axial-Piston Pump, or in which the mechanism which drives the pistons is set at an angle adjustable with the cylinder block; gear-type pump, which may be spur, helical or herringbone gears, variations of internal gears, or a screw pump; or vane pumps. The valves may be stop valves, reversing valves, pilot valves, throttling valves, sequence valves, relief valves, servo valves, non-return valves, poppet valves or unloading valves. Fluid motors are usually constantor variabledischarge piston pumps caused to rotate by the pressure of the hydraulic fluid of the system with the power supplied by the pump power source. Such a hydraulic motor may be used in connection with a variable-discharge pump to form a variable-speed transmission.

The compounds and mixtures of compounds of this invention when utilized as a functional fluid can also contain dyes, pour point depressants, metal deactivator, acid scavengers, antioxidants, defoamers in concentration sufficient to impart antifoam properties, such as from about 10 to about parts per million, viscosity index improvers such as polyalkylacrylates, polyalkylmethacrylates, polycyclic polymers, polyurethanes, polyalkylene oxides and polyesters, lubricity agents and the like.

It is also contemplated Within the scope of this invention that the compounds or mixtures of compounds of this invention can be utilized singly or as a fluid composition containing one or more of the compounds of this invention and one or more additional base stocks in varying proportions.

Typical examples of additional base stocks are hydrocarbon phosphorus ester base stocks such as hydrocarbon phosphates, examples of which are trialkyl phosphates, triaryl and/or substituted aryl phosphates and mixed aryl and/ or substituted-arylalkyl phosphates. One or more substituents, preferably no more than 2, can be attached to the aryl radical and include by way of example halogen, alkyl, haloalkyl and aroxy. Preferred substituents on the aryl group are halo and alkyl and with respect to the halo atom it is preferred that such halo atom be chloro and/or bromo and occupy the meta position. In addition, the above three groups of phosphate base stocks can be defined by the number of carbon atoms present in the alkyl group and the aryl and substituted-aryl group, respectively, and with respect to the alkyl groups, it is preferred to have from about 2 to about 18 carbon atoms, more preferably from about 2 to about 12 carbon atoms and with respect to the number of carbon atoms present in the aryl and substituted aryl groups, it is preferred to have from about 6 to about 16 carbon atoms and more preferably from about 6 to 12 carbon atoms. Additional typical examples of phosphates are dibutylphenyl phosphate, triphenyl phosphate, tricresyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate and mixtures of the above phosphates, such as mixtures of tributyl phosphate and tricresyl phosphate and mixtures of isooctyldiphenyl phosphate and 2-ethylhexyldiphenyl phosphate and mixtures of trialkyl phosphates and tricesyl phosphates and the like.

Additional examples of base stocks are the amides of an acid of phosphorus, that is, mono-, diand triamides of an acid of phosphorus, examples of which are:

phenyl-methyl-N,N-dimethylphosphoroamidate, phenyl-methyl-N,N-di-n-butylphosphoroamidate, mixtures of phenyl-m-cresylN,N-dimethylphosphoroamidate and phenyl-p-cresyl-N,N-dimethy1phosphoroamidate, mixtures of m-cresyl-p-cresyl-N,N-dimethylphosphoroamidate, di-m-cresyl-N,N-dimethylphosphoroamidate, di-p-cresyl-N,N-dimethylphosphoroamidate, di-m-bromophenyl-N-methyl-N-n-butylphosphoroamidate, di-m-chlorophenyl-N-methyl-N-n-butylphosphoro amidate, di-alpha,alpha,alpha-trifluoro-m-cresyl-N-methyl-N-n butylphosphoroamidate, di-p-bromophenyl-N-methyl-N-n-isoamylphosphoroamidate, di-p-chlorophenyl-N-methyl-Nm-isoamylphosphoroamidate, p-chlorophenyl-m-bromophenyl-N-methyl-N-n-isoamylphosphoroamidate, phenyl-N-methyl-N-butyl-N'-methyl-N'-butylphosphorodiarnidate, phenyl-N,N-di-n-butyl-N',N'-di-n-butylphosphorodiamidate, phenyl-N,N-dimethyl-N,N-dimethylphosphorodiamidate, m-chlorophenyl-N-methyl-N-n-butyl-N-methyl-N'-nbutylphosphorodiamidate, m-bromophenyl-N-methyl-N-n-butyl-N'-methyl-N'-nbutyl-N'-methyl-N-n-butylphosphorodiamidate, p-chlorophenyl-N-methyl-N-isobutyl-N-methyl-N'- isoamylphosphorodiamidate, p-bromophenyl-N-methyl-N-isobutyl-N-methyl-N'- isoamylphosphorodiamidate, N-methyl-Nbutyl-N'-methyl-N-butyl-N"-methyl-N"- butylphosphorotriamidate, N-methyl-N-butyl-N',N"-tetramethylphosphorotriamidate, N-di-n-propyl-N',N"-tetramethylphosphorotriamidate,

and N,N'-di-n-propyl-N"-dimethylphosphorotriamidate.

Typical examples of phosphinate ester base stocks are:

phenyl-di-n-propyl phosphinate, phenyl-di-n-butyl phosphinate, phenyl-di-sec-butyl phosphinate, phenyl-di-n-pentyl phosphinate, phenyl-di-neopentyl phosphinate, phenyl-di-n-hexyl phosphinate, phenyl-di-n-butyl thiophosphinate, p-methoxylphenyl-di-n-butyl phosphinate, m-chlorophenyl-di-n-butyl phosphinate phenyl-(n-propyl-n-pentyl) phosphinate, phenyl-(n-propyl-n-butyl) phosphinate, phenyl-(n-propyl-n-hexyl) phosphinate, phenyl-(n-butyl-n-pentyl) phosphinate, phenyl- (n-butyl-n-hexyl) phosphinate, phenyl-(n-pentyl-n-hexyl) phosphinate, phenyl-(neopentyl-n-propyl) phosphinate, phenyl- (neopentyl-n-butyl phosphinate, phenyl-(neopentyl-n-hexyl) phosphinate, thiophenyl-di-n-propyl phosphinate, thiophenyl-di-n-pentyl phosphinate, cresyl-di-n-pentyl phosphinate, tert-butylphenyl-di-n-butyl phosphinate, n-butylphenyl-di-n-butyl phosphinate, sec-butylphenyl-di-n-butyl phosphinate, ethylphenyl-di-n-butyl phosphinate, xylyl-di-n-butyl phosphinate,

8 thiophenyl-di-n-hexyl phosphinate, thiophenyl-di-n-butyl phosphinate, thiophenyl-di-n-propyl thiophosphinate, thiophenyl-di-n-butyl thiophosphinate, thiophenyl-di-n-pentyl thiophosphinate, thiophenyl-di-n-hexyl thiophosphinate, thiophenyl-(n-propyl-n-butyl) phosphinate, thiophenyl-(propyl-n-pentyl) phosphinate, thiophenyl-(n-propyl-n-hexyl) phosphinate, thiophenyl-(n-butyl-n-pentyl) phosphinate, thiophenyl-(n-butyl-n-hexyl) phosphinate, thiophenyl-(n-pentyl-n-hexyl) phosphinate, thiophenyl-(n-propyl-n-butyl) thiophosphinate, thiophenyl-(n-propyl-n-pentyl) thiophosphinate, thiophenyl-(n-propyl-n-hexyl) thiophosphinate, thiophenyl-(n-butyl-n-pentyl) thiophosphinate, thiophenyl- (n-butyl-n-hexyl) thiophosphinate, and thiophenyl-(n-pentyl-n-hexyl) thiophosphinate.

Additional examples of base stocks are orthosilicates examples of which include the tetraalkyl orthosilicates such as tetra(octyl)orthosilicates, tetra(2-ethylhexyl)orthosilicates and the tetra(isooctyl)orthosilicates and those in which the isooctyl radicals are obtained from isooctyl alcohol which is derived from the 0x0 process, and the (trialkoxysilico)trialkyl orthosilicates, otherwise referred to as hexa(alkoxy) disiloxanes, such as hexa(Z-ethylbutoxy) disiloxane and hexa(Z-ethylhexoxy) disiloxane.

The preferred tetraalkyl orthosilicates and hexa(alkoxy) disiloxanes are those in which the alkyl or alkoxy radicals have from 4 to 12 carbon atoms and in which the total number of carbon atoms in the orthosilicate is from 16 to 60.

In addition to the hexa(alkoxy) disiloxanes referred to above, other preferred hexa(alkoxy) disiloxanes are those in which the alkyl radical of the alkoxy groups are selected from l-ethylpropyl, 1,3-dimethylbutyl, 2-methylpentyl, l-methylhexyl, l-ethylpentyl, 2-butylhexyl and 1-methyl-4-ethyloctyl.

Another class of base stocks are siloxanes, examples of which are poly(methyl) siloxane, poly(methyl, phenyl) siloxane, poly(methyl, chlorophenyl) siloxane and poly- (methyl, 3,3,3-trifluoropropyl) siloxane.

Additional base stocks are dicarboxylic acid esters, polycarboxylic acid esters and complex esters representative of which are di(2-ethylhexyl) azelate, di(Z-ethylhexyl) sebacate, diisooctyl sebacate, 2-ethylhexyl 3:5 :5 trimethylhexyl sebacate, diisooctyl azelate, di(3:5 :5 trimethylhexyl) se bacate, di(1-methyl-4-ethyloctyl) sebacate, diisodecyl azelate, diisotridecyl azelate, di(l-methyl- 4-ethyloctyl) glutarate, di(Z-ethylhexyl) adipate, di(3- methylbutyl) azelate, di(3:5 :5 trimethylhexyl) azelate, di(Z-ethylhexyl) adipate, di(C 0X0) adipate, bis(di-eth ylene glycol monobutyl ether) adipate, di(isooctyl/isodecyl) adipate, diisotridecyl adipate, triethylene glycol di(Z-ethylhexanoate), hexanediol 1,6-di(2-ethy1hexanoate), trimethylolpropane, tri-n-pelargonate, trimethylolpropane tricaprate, trimethylolpropane tricaprylate, the trimethylolpropane triester of mixed octanoates, pentaerythrityl tetrabutyrate, pentaerythrityl tetravalerate, pentaerythrityl tetracaproate, pentaerythrityl dibutyrate dicaproate, pentaerythrityl butyrate caproate divalerate, pentaerythrityl butyrate trivalerate, pentaerythrityl butyrate tricaproate and pentaerythrityl tributyrate caproate. Suitable dipentaerythrityl esters include dipentaerythrityl hexavalerate, dipentaerythrityl hexacaproate, dipentaerythrityl hexaheptoate, dipentaerythrityl hexacaprylate, dipentaerythrityl tributyrate, tricaproate, dipentaerythrityl trivalerate trinonylate, dipentaerythrityl mixed hexaesters of C -C fatty acids and complex esters which are esters prepared from methylene glycol (1 mole), adipic acid (2 moles) and 2- ethylhexanol (2 moles); esters prepared from tetraethylene glycol (1 mole), sebacic acid (2 moles), and 2- ethylhexanol (2 moles); esters prepared from 2-ethyl- 1,3-hexanediol (1 mole), sebacic acid (2 moles) and 2- ethylhexanol (2 moles); esters prepared from diethylene glycol (1 mole), adipic acid (2 moles )and n-butanol (2- moles); esters prepared from polyglycol 200- (1 mole), sebacic acid (2 moles) and ethylene glycol mono(2-ethylbutyl) ether (2 moles); esters prepared from sebacic acid (1 mole), tetraethylene glycol (2 moles) and caproic acid (2 moles); esters prepared from triethylene glycol (1 mole), adipic acid (1 mole), n-caproic acid (1 mole) and 2-ethylhexanol (1 mole); esters prepared from sebacic acid (1 mole), lactic acid (2 moles) and n-butanol (2 mols); esters prepared from tetraethylene glycol (1 mole), lactic acid (2 moles) and butyric acid (2 moles); complex esters prepared from neopentyl glycol (2 moles), dicarboxylic acids (1 mole) and monocarboxylic acids (2 moles) and complex esters prepared from neopentyl glycol (1 mole), dicarboxylic acids (2 moles) and monohydric neoalcohols, e.g., 2,2,4-trimethylpentanol (2 moles).

While this invention has been described with respect to 10 various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claim.

The embodiments of this invention in which an exclusive property or privilege is claimed are deifined as follows:

1. The compound bis(mbromophenoxy) dimethyl silane.

References Cited George et al., J.O.C., 25, September 1960, p. 1646. Speier, J.A.C.S., 74, February 1952, p. 1005.

JAMES E. POER, Primary Examiner PAUL F. SHAVER, Assistant Examiner US. Cl. X.R. 

